The new work and pensions secretary has suggested the government’s pledge to halve the disability employment gap will face lengthy delays, after he said he wanted to spend a “few years” testing how to achieve the target.

Tory ministers have repeatedly referred to their commitment to halving the gap of about 30 percentage points between the employment rates of disabled people (less than 50 per cent) and non-disabled people (about 80 per cent).

Halving the gap would mean finding jobs for more than one million more disabled people.

Last year’s general election manifesto said a Conservative government would “aim to halve the disability employment gap”, one of just eight mentions of the words “disabled” or “disability” in the 84-page document.

Labour MP Neil Coyle (pictured during the session), a former director of Disability Rights UK, asked Crabb what “milestones” he would use to measure the success of the “very welcome and ambitious manifesto commitment” to halve the disability employment gap, when the proportion of working-age disabled people in work had fallen over the last six years.

Disability Rights UK has stressed the importance of setting milestones, in its submission to the committee’s inquiry into halving the gap, pointing out that “interim targets could be expected to drive institutional change and it could be expected that the government would wish to know if it was on track”.

But Crabb said that rather than setting interim targets for narrowing the gap, he wanted instead to focus on what policies might prove successful.

He said that 150,000 more disabled people were in work in the last year, but if the number of non-disabled people in work had also risen “there is no closing of the gap”.

He said he did not think that setting out interim targets towards achieving the aim of halving the gap was “the more helpful approach”, and added: “The more helpful approach I think is testing what works and building the evidence base for how we do that and that’s what I want to spend the next few years really focusing on.”

He appeared then to criticise the approach of his predecessor as work and pensions secretary, by adding: “I don’t know that whatever has gone on before has really built a strong evidence base for supporting people with disabilities and health conditions into work.”

Crabb told the committee that he wanted to “take a step back” from previous plans to publish a white paper with “firm legislative proposals” on supporting disabled people into work.

Instead, he said, there would be a “much more discursive green paper that starts to reframe the issue and points the way towards more meaningful long-term reform”.

And he said he wanted to “restart conversations with disability organisations and disabled people themselves about how best as a government we can work with them to close the disability employment gap”.

When Crabb said later in the session that DWP would provide more disability experts in jobcentres, Coyle asked him to clarify what this increase meant, as the number of disability employment advisers fell by a fifth in the last parliament.

In another criticism of the Duncan Smith regime, Crabb said DWP would be placing another 500 disability employment advisers into jobcentres across the country, which he said was “a significant step forward”.

He said: “Whatever decisions happened in the last parliament, that was then.

“I’m pretty clear in my mind, whether it’s by employing more of our own people as disability specialists or partnering with expert organisations, we need to get more expertise under the roof of Jobcentre Pluses, in terms of how we support people with sicknesses and disabilities, and addictions as well.”

A Department for Work and Pensions spokesman said later that there was “no plan to abandon the target” of halving the disability employment gap.

He said: “It is a long-term ambition, and the secretary of state was re-affirming government’s commitment to reducing the gap.”